1. Field of the Invention
The present invention relates to a method of severing a paper web suited to separating a preset length of paper from the web.
The invention also concerns an apparatus suited to implement the method.
2. Description of the Related Art
The use of perforated paper web increases with the growing number of computer applications. Paper is conventionally packed in folded form in stacks, whereby the long paper web is perforated at the folds. The paper is fed to a printing machine or printer, after which the paper is severed to sheets of desired length as necessary.
In prior-art applications the perforated paper web has been severed manually without the use of tools. Alternatively, the paper web has been severed against a toothed blade extending over the width of the web by pressing the web either manually or with the help of a mechanical device against the blade. Cutting-blade severing devices are also conventionally used, whereby a nonperforated paper web can be cleanly severed.
According to the U.S. Pat. Nos. 3,794,228 and 4,946,082, a paper web resting on clamping elements is severed by tensioning the web by means of a severing element placed between said clamping elements. In such arrangements the separation line of the perforated continuous form is transferred to coincide with the severing element, the form is clamped in place by two frictional clamp surfaces and the severing element is projected against the tensioned, clamped web, whereby the paper web is severed at the perforation line. Such apparatuses achieve a short work cycle of separation, but they are not applicable to severing the so-called manufacturer-identifying logotype label web and separating the label from the web.
The perforated manufacturer-identifying logotype label web is a continuous form which carries a chain of labels separated from each other by a first perforation. The upper or lower edge of the labels have a manufacturer's identifier area separated from the basic part of label by a second perforation. Such a label web is used for marking a product without information on the manufacturer or vendor. For example, if not all manufactured paper rolls are desired to be marked so as to include the manufacturer's logotype for reasons related to retail or other specific sales activities wherein a simple conventional label containing paper roll information only is desired, such a logotype label web is advantageously used. Retailers and paper warehouses also typically request their paper orders to be delivered without the manufacturer's identification so as to permit the identification of the paper by their own logotype prior to retail sales deliveries. Perforated logotype label web allows the use of single printer fed by a single type of continuous form for printing both the identifier-free and logotype-identifier containing labels. The nonidentifying label is produced by simply separating the basic part of the label along the first perforation before placing the label onto the roll. Prior to the availability of the logotype label web, the printing and placing of the identifier-free and logotype-identifier containing labels needed the use of two label printers.
The logotype area is today separated from the label web by means of various cutting blade devices or the logotype area can be separated using the same cutting apparatus which serves for separating the labels from the continuous form. For current applications such severing methods have, however, an excessively long work cycle of separating the logotype area. In the cutting blade-type severing methods, the feed of the continuous form must be stopped and the form clamped for the duration of the severing operation. When a single severing device is also used for separating the logotype area, two cutting operations must be performed, whereby the duration of the work cycle is obviously doubled.